(a) Field of the Invention
The present invention relates to a display device. More specifically, the present invention relates to a demultiplex device and method for demultiplexing data current in a display device.
(b) Description of the Related Art
FIG. 1 shows an active matrix organic light emitting diode (AMOLED) display device as an example of a current-driven display device for which current demultiplexing is desirable.
The illustrated current-driven display device includes organic electroluminescent (EL) display panel 100, data driver 200, current demultiplexer 300, and scan drivers 400, 500.
A predetermined data current is applied to pixels 10 belonging to scan lines selected by scan drivers 400, 500, and pixels 10 display colors corresponding to the data current. Current demultiplexer unit 300 is used to reduce the number of integrated circuits (ICs) of data driver 200. That is, the current provided by data driver 200 is demultiplexed 1:N by demultiplexer unit 300, and is applied to the pixels corresponding to the N data lines. Usage of demultiplexer unit 300 reduces the number of ICs used for the data driver and helps save purchase costs.
FIG. 2 shows a conventional analog switch for a demultiplexer. The 1:2 demultiplexer shown in FIG. 2 includes switches S11, S12 which are alternately switched to output the data current to two data lines. A long time is generally required to program the data to pixels 10 in order to realize high resolution in the current-driven panel. However, a reduction of the number of ICs of the data driver implies that the data programming time must also be generally reduced. Thus, conventional demultiplexers are not suitable for high-resolution display devices.